PURPOSE: To offer the font control mechanism which controls font information independently of an application program.

CONSTITUTION: A definition file 2 holds the correspondence relation among system-side font names, printing font names, screen display font names and dictionary file names, and a dictionary file 3 holds font metric information on the printing fonts. A font manager part 1 generates a control table TB according to the contents of the definition file 2 and a font metric dictionary 12 according to the table and dictionary file 3, retrieves the control table TB and sends the corresponding font name back in response to inquiries for the printing font name and screen display font name corresponding the system-side font name from the application program 5, and retrieves the font metric dictionary 12 and returns the corresponding font metric information in response to an inquiry for the font metric information on each character.